What problems might a vehicle experience under different load conditions without a leveling valve?

Without a leveling valve, a vehicle can experience a number of problems under different load conditions. When the load changes, the height of the vehicle body cannot be automatically adjusted, resulting in inconsistent vehicle heights under different loads. For example, the rear of the vehicle may sink when passengers or cargo are added, and may be too high when the load is reduced.
The impact of body height inconsistency on vehicle stability is profound and multifaceted. During driving, especially when the vehicle is traveling at high speeds or performing dynamic operations such as sharp turns, this height difference will significantly change the distribution of the vehicle's center of gravity. The instability of the center of gravity will not only cause obvious shaking and swaying of the vehicle, but may also cause the body to roll, greatly reducing the stability of driving. This unstable driving state not only tests the driver's control ability, but also greatly affects the riding experience of passengers, making them feel uncomfortable or even panic.
If the suspension system operates under frequently changing load conditions for a long time and lacks effective adjustment of the leveling valve, the suspension system will face unprecedented challenges. As a common form of suspension in modern high-end vehicles, air suspension and its connecting components will suffer additional mechanical stress and fatigue damage during frequent compression and tension processes. This long-term, high-intensity stress will accelerate the aging and cracking of the airbag material, and even cause the connecting parts to loosen or break, thus seriously affecting the overall performance and life of the suspension system.
What's more serious is that reduced stability and damage to the suspension system may directly threaten driving safety. In situations where vehicles need to respond quickly, such as emergency braking or rapid lane changes, vehicles with inconsistent heights are more likely to suffer out-of-control phenomena, such as sideslip and tail-drifting, which greatly increases the risk of traffic accidents. In addition, due to the failure of the suspension system, the vehicle may not be able to effectively absorb road vibrations during driving, resulting in a reduction in the adhesion between the tires and the ground, further weakening the vehicle's handling and stability.
For passengers, the inconsistency in vehicle body height also leads to a sharp decrease in ride comfort. They will feel continuous bumps and shaking during driving, which will not only affect their rest and relaxation, but may also cause discomfort such as motion sickness. During long-distance travel, this discomfort may be infinitely amplified, causing adverse effects on the physical and mental health of passengers.
In addition, inconsistencies in body height can have a negative impact on a vehicle's fuel economy. Due to the increase in air resistance and rolling resistance, the vehicle needs to consume more fuel or electrical energy to maintain its motion. This not only increases the operating costs of car owners, but also exacerbates environmental pollution problems.
For vehicles with multiple carriages, the height difference between each carriage may also pose a threat to the overall operating safety of the train. When passing a curve or performing emergency braking, relative displacement or misalignment may occur between carriages with inconsistent heights, thereby increasing the risk of decoupling of the coupling device. Once a decoupling accident occurs, the consequences will be disastrous. Therefore, maintaining a high degree of consistency between carriages is crucial to ensuring the safety of train operations.